State Key Lab of Fine Chemicals, Dalian University of Technology, Dalian 116024, China; Faculty of Light Industry and Chemical Engineering, Dalian Polytechnic University, Dalian 116034, China.
State Key Lab of Fine Chemicals, Dalian University of Technology, Dalian 116024, China.
Carbohydr Polym. 2015 Jan 22;115:177-85. doi: 10.1016/j.carbpol.2014.08.041. Epub 2014 Aug 27.
A new regenerable adsorbent was successfully prepared by modifying maize straw (MS) with succinic anhydride in xylene. The succinylated-maize straw (S-MS) was characterized by FTIR, solid-state MAS (13)C NMR spectroscopy, SEM-EDX and point of zero charge analysis. NaS-MS was successfully obtained after deprotonating the carboxylic acid groups of S-MS by Na2CO3 solution. Batch experiments were carried out with NaS-MS for the removal of Cd(II). The effects of pH, adsorbent dosage, contact time, initial concentration and temperature were investigated. The experimental data were best described by a pseudo-second-order kinetics and Langmuir adsorption models. Thermodynamic parameters (ΔG, ΔH, and ΔS) were also calculated from data obtained from experiments performed to study the effect of temperatures. NaS-MS could be regenerated at least five times in saturated NaCl solution without any loss. Furthermore, ∼97% of adsorbed Cd(II) ions could be recovered as the metal oxide. Finally, the adsorption mechanism of NaS-MS was discussed.
一种新型可再生吸附剂通过在二甲苯中用琥珀酸酐对玉米秸秆（MS）进行改性成功制备。琥珀酰化玉米秸秆（S-MS）通过傅里叶变换红外光谱（FTIR）、固态 MAS（13）C NMR 光谱、扫描电子显微镜-能量色散 X 射线能谱（SEM-EDX）和零电荷点分析进行了表征。通过 Na2CO3 溶液将 S-MS 中的羧酸基团脱质子化，成功获得了 NaS-MS。使用 NaS-MS 进行批处理实验，以去除 Cd(II)。考察了 pH 值、吸附剂用量、接触时间、初始浓度和温度的影响。实验数据最好用伪二级动力学和 Langmuir 吸附模型来描述。还根据实验数据计算了热力学参数（ΔG、ΔH 和 ΔS），以研究温度的影响。在饱和 NaCl 溶液中，NaS-MS 至少可以再生五次，而不会有任何损失。此外，约 97%的吸附 Cd(II)离子可以作为金属氧化物回收。最后，讨论了 NaS-MS 的吸附机理。
